Multiple-input multiple-output (MIMO) systems include multiple transmit antennas and multiple receive antennas. MIMO systems provide improved reliability over fading channels, because the increased dimension of a MIMO system may be used to mitigate signal-level fluctuations. Transmit beamforming with receive combining is a method to exploit the diversity offered by MIMO systems. The beamforming techniques for narrowband channels may be extended to frequency selective MIMO channels by employing orthogonal frequency division multiplexing (OFDM). The use of MIMO technology in combination with OFDM, e.g., “MIMO-OFDM,” converts a broadband MIMO channel into multiple narrowband MIMO channels corresponding to OFDM subcarriers.